%%% Copyright 2010 Google Inc.
%%%
%%% Licensed under the Apache License, Version 2.0 (the "License");
%%% you may not use this file except in compliance with the License.
%%% You may obtain a copy of the License at
%%%
%%%     http://www.apache.org/licenses/LICENSE-2.0
%%%
%%% Unless required by applicable law or agreed to in writing, software
%%% distributed under the License is distributed on an "AS IS" BASIS,
%%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%%% See the License for the specific language governing permissions and
%%% limitations under the License.

%%% @copyright 2010 Google Inc. All Rights Reserved.
%%% @author <jacoby@google.com> Full Name [http://sites/madcloud]
%%% @version {@version}
%%% @doc
%%% Trace utility module. Use from shell started with `make trace'.

-module(trace).

-define(DEV_NODE, "dev@").

-export([start/0, module/1]).

%% Starts dbg tracing on the dev node.
start() ->
  dbg:stop_clear(),
  dbg:start(),
  dbg:tracer(),
  dbg:n(get_dev_node()),
  dbg:p(all, c).

%% Adds a module to the trace.
module(Mod) ->
  dbg:tpl(Mod, '_', '_', []).

%% Constructs the remote nodename to trace.
get_dev_node() ->
  NodeString = atom_to_list(node()),
  ["trace", Localhost] = string:tokens(NodeString, "@"),
  list_to_atom(?DEV_NODE ++ Localhost).
